Merge branch 'bbr2-testing' of https://github.com/esnet/iperf into bbr2-testing

src/iperf_client_api.c

@@ -51,12 +51,14 @@
 #endif /* TCP_CA_NAME_MAX */
 #endif /* HAVE_TCP_CONGESTION */
 
+
 int
 iperf_create_streams(struct iperf_test *test, int sender)
 {
     int i, s;
 #if defined(HAVE_TCP_CONGESTION)
     int saved_errno;
+    static int sender_id = 0; /* use this to set congestion control based on even or odd */
 #endif /* HAVE_TCP_CONGESTION */
     struct iperf_stream *sp;
 
@@ -72,13 +74,30 @@ iperf_create_streams(struct iperf_test *test, int sender)
 #if defined(HAVE_TCP_CONGESTION)
 	if (test->protocol->id == Ptcp) {
 	    if (test->congestion) {
-		if (setsockopt(s, IPPROTO_TCP, TCP_CONGESTION, test->congestion, strlen(test->congestion)) < 0) {
-		    saved_errno = errno;
-		    close(s);
-		    errno = saved_errno;
-		    i_errno = IESETCONGESTION;
-		    return -1;
+                if(sender_id % 2 == 0) { /* CC testing hack: only do this for even numbered senders */
+	            /*
+	            printf("setting cong cntrl on stream %d to %s \n",sender_id,test->congestion);
+		    */
+		    if (setsockopt(s, IPPROTO_TCP, TCP_CONGESTION, test->congestion, strlen(test->congestion)) < 0) {
+		        saved_errno = errno;
+		        close(s);
+		        errno = saved_errno;
+		        i_errno = IESETCONGESTION;
+		        return -1;
+		    } 
 		} 
+#ifdef ADD_SLEEP /* did not seem to really matter, so removing for now */
+		else { 
+			/* for CC hack: sleep N seconds to give even numbered streams (eg: cubic) a head start */ 
+                    int sleep_time = 1;
+                    /*
+	            printf("default cong cntrl on stream %d \n",sender_id);
+	            printf("sleeping for %d seconds to let stream %d have a head start \n",sleep_time, sender_id-1);
+                    */
+		    sleep(sleep_time);
+                }
+#endif
+                sender_id++;
 	    }
 	    {
 		socklen_t len = TCP_CA_NAME_MAX;
@@ -348,13 +367,6 @@ iperf_connect(struct iperf_test *test)
         return -1;
     }
 
-    // set TCP_NODELAY for lower latency on control messages
-    int flag = 1;
-    if (setsockopt(test->ctrl_sck, IPPROTO_TCP, TCP_NODELAY, (char *) &flag, sizeof(int))) {
-        i_errno = IESETNODELAY;
-        return -1;
-    }
-
     if (Nwrite(test->ctrl_sck, test->cookie, COOKIE_SIZE, Ptcp) < 0) {
         i_errno = IESENDCOOKIE;
         return -1;

src/iperf_tcp.c

@@ -375,6 +375,7 @@ iperf_tcp_connect(struct iperf_test *test)
     socklen_t optlen;
     int saved_errno;
     int rcvbuf_actual, sndbuf_actual;
+    useconds_t sleepTime;
 
     if (test->bind_address) {
         memset(&hints, 0, sizeof(hints));
@@ -397,6 +398,14 @@ iperf_tcp_connect(struct iperf_test *test)
         return -1;
     }
 
+    /* for CC hack, sleep for a random number of usec between 0 and 500 ms */ 
+    /*
+    srand(time(0));
+    sleepTime = (useconds_t)(((rand() % 5) + 1) * 1000); 
+    printf("DEBUG: sleeping for %d us \n", sleepTime); 
+    usleep(sleepTime);
+    */
+
     if ((s = socket(server_res->ai_family, SOCK_STREAM, 0)) < 0) {
 	if (test->bind_address)
 	    freeaddrinfo(local_res);